Device for rectifying alternating current



Aug. 5, 1930. P. w. DOIBBENI 1,772,133

DEVICE FOR RECTIFYING ALTERNATINGCURRENT Filed July 23, 1926 Invemon 6am WM m Patented Aug. 1930 T H I UNITED STATES PATENT OFFICE FIETEB WILHELM DOBBEN, OF 'EINDHOVEN, NETHERLANDS, ASSIGNOB TO N. V. PHILIPS GLOEILAMPENFABRIEKEN, OF EINDHOVEN, NETHERLANDS DEVICE FOR RECTIFYING ALTERNATING CURRENT Application filed July 23, 1926, Serial No. 124,440, and in the Netherlands October 7, 1925.

This invention has for its object when usfor the cases which in practice mostly occur, ing discharge tubes as rectifiers for high in the neighbourhood of 1 microfarad. tensions e. g. of about 80 v. to prevent the The invention will be more clearly underbattery which has to be charged from being stood by referring to the accompanying'drawdischarged in consequence of the fact that ings in which the supply of alternating current suddenly igure 1 represents a rectifying installaceases, which may occur either when the al tion comprising one discharge tube so that ternating current is switched off on the prione half of the alternating current wave is mary side of the transformer or when in rectified. T refers to a transformer, R to a 10 consequence of a disturbance in the supply resistance, G to a capacity, G to a rectifying of electricity the alternating current sudtube and B to a battery which has to be denly fails. char ed. If, when the transformer is After the battery which has tobe charged switc ed off, an inductive impulse is produced has been connected to the rectifier and the in the direction indicated by the arrow, the

1.", latter to the alternating current network, the. battery would be dischargedbut for the batteries are automatically charged so that, capacity C. Now, however, the current imgenerally speaking, supervision is not needed. pulse is received by the condenser and a re- However,'with rectifying apparatus for turn impulse in the discharge tube is pre-' high tensions e. g. 80 volts and upwards, it is vented.

2 ,known that when the transformer is switched Figure 2 represents a rectifying installa- 70. oil on its primary side, there takes place in tion whereby the two halves of the alternatthe discharge tube, in consequence of the ining current wave are rectified. If in this case ductive impulse then produced, a discharge an inductive impulse in the direction indiin the wrong direction and constquentl an cated by the arrow is produced, the battery 2:, electron current flowing from tlze ano e to might be discharged through G which, howthe cathode, which ma result in the battery ever, is'now prevented by the condenser G being discharged. cans to prevent the What I claim is batteries from being discharged in conse- 1. An alternating-current rectifying dequence of the said phenomenon have not been vice comprising an electric discharge tube :m known hitherto; stress has therefore always supplied by a transformer and acondenser been laid on the fact that for causing the having a capacity of the order of one microcharging of the battery to cease, it is necesfarad connected in parallel to said discharge -sary first to unscrew the rectifying lamp and tube.

then to switch off the transformer. It is 2. An alternating current rectifying detherefore not advisable to charge the batvice comprising at least one discharge tube tery without supervision for example during supplied by a transformer and a condenser the night, for it may happen that for some in parallel to said discharge tube of such a reason or other the supply of alternating cutcapacity that it is effective to store inducrent ceases so that the battery may be distive impulses taking place in the secondary 40 charged instead of charged. winding of the transformer, so that the ten- The invention provides a means to charge sion at the cathode does not increase so much even high tension batteries without any superthat a discharge in the wrong direction in vision. A condenser is connected in aralthe tube may occur.

1el to the rectifying tube; when now t e al- In testimony whereof I afiix my signature 45 ternating'current fails, the energy in the at the city of Eindhoven, this first day of secondary circuit produced in consequence July, A. D. 1926. of the inductive impulse, will be received by PIETER WILHELM DOBBEN. the condenser and a discharge in the wrong direction will not be produced. The best 50 value for the capacity of this condenser lies 

